quacky1
/ˈkwaki/informal
adjective
Inclined to or characterized by quackery.
Origin
Mid 19th century; earliest use found in The Southern Literary Messenger. From quack + -y.
quacky2
/ˈkwaki/adjective
That is, or is like, a quack; having the harsh quality characteristic of a duck's cry.
Origin
Late 19th century; earliest use found in Forum. From quack + -y.